Made of high quality alloy steel (chrome-molybdenum) Engineered specifically for use with impact tools using the most up to date industrial specifications Tested to the highest specifications to deliver outstanding performance at the competitive cost Lifetime Warranty Grey Pneumatic sockets are designed for professional tool users. This socket features our "high torque" drive. This limits the amount of wear on the corners of the fastener and the socket. It also improves the strength of the socket, transfers increased torque to the fastener and allows easier access to tight areas. Most Socket Sets products are available for in-store pickup from Advance Auto Parts.